+is($x->description, "\x{100}blah", 'description memoized');
+
+$x->{name} = "2\x{100}wide";
+$x->{newsgroup} = '2.wide';
+like($x->mailboxid, qr/\AM32c48077696465-[0-9a-f]+\z/,
+ '->mailboxid w/o slice (JMAP)');
+like($x->mailboxid(78), qr/\AM322e77696465-4e-[0-9a-f]+\z/,
+ '->mailboxid w/ slice (IMAP)');